Brake-slack adjuster



(No Moael.) 2 Sheets-Sheet 1. F. ROBINSON.

BRAKE SLACK ADJUSTER. No. 535,772. Patented Mar. 12, 1895.

(No Model.) 2 Sheets-Sheet 2..

P. ROBINSON.

BRAKE SLAGK ADJUSTER. No. 535,772. Patented Mar. 12, 1895,

n'rnivr 1 errors.

FRANK ROBINSON, OF BANGOR, ASSIGNOR OF ONE-HALF TO JAMES ll. SEWALL, OFPORTLAND, MAINE.

BRAKE-SLACK ADJUSTER.

SPECIFICATION forming part of Letters Patent No. 53 5,772, dated March12, 1895.

App n filed December 8, 1894:. Serial No. 531,233. (No model.)

To all whom it may concern:

Be it known that I, FRANK ROBINSON, a citizen of the United States,residing at Bangor, in the county of Penobsoot and State of Maine, haveinvented certain new and useful Im provements in Brake SlackAdjusters,-of which the following is a specification, reference beinghad therein to the accompanying drawings.

The invention consists in the construction of an automatic slackadjuster applied between the cylinder levers, and so constructed thatthe adjustment is effected Without connecting the adjusting devices to astationary part of the car.

The invention particularly consists in the construction of a two-partfulcrum rod having a central take-up connection, and a twopartadjustment rod, likewise connecting these two levers beyond the fulcrumrod, having a take up connection, one cylinder lever having a limitedamount of lost motion or a play on the adjustment rod, the parts beingso constructed and combined as to maintain a substantially constanttravel of the air brake piston at all times, regardless of the wear ofthe shoes, all as more fully hereinafter described.

In the drawings, Figure 1 is a plan view of the cylinder and cylinderlevers showing my invention applied thereto. Fig. 2 is a side elevation,partly in section of the adjustment rod. Fig. 3 is a side elevation of atake-up connection of slightly modified form. Fig.4 is a sectiontherethrough. Figs. 5 and 6 are diagram plans showing the differentpositions of the parts in operation.

A is the air brake cylinder.

13 and O are the two cylinder levers, the lever B being pivoted to thebracket D at one end of the cylinder and the cylinder lever 0 beingconnected to the piston rod E. These levers at their ends have connectedto them the usual rods which operate brakes at the opposite ends of thecars in the well known manner. The two levers are connected together ator near their middle by a tie-rod, which I call the fulcrum rod. Thisfulcrum rod is made in two parts F and F. On the inner end of thesection F is an open box like socket or guide G in which the end of thesection F of the rod slidingly engages. Upon the upper face of thissection F is formed a ratchet bar H.

I is a toothed block or pawl slidingly engaging in avertical aperture inthe top of the box G on the section F of the fulcrum rod, and I is aspring acting to hold this block in engagement with the ratchet bar H asplainly shown in Fig. 2. This construction of .takeup joint between thetwo members of the fulcrum rod is especially desirable as the ratchetbar and pawl are entirely inclosed, so that there is no danger of thedust or dirt interfering with their movement, or the positive engagementof the pawl with the ratchet bar.

At a point at or near the ends of the levers B and G is a rod made intwo sections J and J, their meeting ends overlapping and having asimilar take up connection. The section J is pivoted to the lever B. Thesection J is provided at its end with a loop or guideway K in whichslidin-gly engages the lever C.

K is a pin adapted to be engaged in any one of a series of apertures Lthrough the loop K and adapted to span the loop so as to lengthen orshorten the guide way or slot in which the lever C may move.

Instead of the construction shown in Fig. 2 I may use the take upconnection, as shown in Figs. 8 and 4. In this construction of takeup Iemploy a series of dogs M supported in transverse grooves or sockets Min the top of the boX portion of the section J engaging with the ratchetbar on the section J.

N is a plate having vertical slots at the ends engaging with pins N soas to permit said plate to have a limited vertical movement, the upperedge of the plate resting uinder the lower edge of the dogs M.

O is a cam journaled on an extension 0 on the under side of the sectionJ and which may be turned to actuate the plate N vertically, therebylifting the dogs out of engagement with a ratchet bar to permit the adjustment or disengagement of the parts of the take-up connection.

P is an end plate detachablysecured in the section J over the end of thesockets M and acting to hold the dogs in position against enddisplacement.

The parts being thus constructed their op eration is as follows: Insetting the brake the parts are adjusted so that with the desired travelof the brake piston, the brakes will be set. When so set, the lever Gwill move back and forth within the loop K without striking the bent endthereof, or the pins K at the other end. The length of this movement canbe varied by adjusting the pin K into the different adjusting holes L.In case the shoes wear so as to give too great a piston travel, theouter end of the levers B and O approach each other, the lever G willstrike the pin K and the take-up rod will thus be under compression atopposite ends between the two cylinder levers, which will effect asliding movement between the overlapping ends of its two sections,thereby shortening that red. The toothed block I engaging in the ratchetbar will hold it in its adjusted position. When thelevers B and 0 returnto their initial position,'the lever G will strike against the end ofthe loop K and thereby cause such lever to fulcrum thereon, when thefurther inward movement of the piston rod E will act to put acompression strain upon opposite ends of the fulcrum bar and shortenthat in the same manner as described for the adjustment bar. WVhen thepiston is again actuated the fulcrum bar being shortened the slack willhave been taken up and the piston will make its usual and desiredtravel.

I deem it especially desirable to apply my adjustment to the cylinderlevers, as it takes up the slack positively and is not affected by thewear of the parts, springing of levers, &c., requiring but a singleadjuster for each car.

Another advantage of my construction is that it does not require anychanges to the brake apparatus as now ordinarily applied, simply the useof the two part fulcrum rod in place of the usual rigid rod, and thetwopart adjustment rod. It can thus be applied to brake equipments nowin use with practically no change therein.

What I claim as my invention is 1. The combination of the cylinderlevers, a fulcrum rod having an intermediate take up, an adjustment rodextending between the levers beyond the fulcrum rod, one end of saidadjustment rod having a loose connection with the lever, and. a take-upin said adj ustment rod, substantially as described.

2. The combination of the cylinder levers, a two-part fulcrum rod,having a ratchet and pawl connection at the meeting ends of the parts, atwo-part adjustment rod pivoted at one end near the outer end of onelever, a loop or eye at the other end through which the other leverengages, and a take up at the meeting ends of the adjustment rod,substantially as described.

3. The combination of the cylinder levers, a two part fulcrum rod havingan intermediate take-up, a two part adjustment rod having a similar takeup, one end of said rod being pivotally connected to one lever, a loopat the other end of the adjustment rod through which the other leverpasses, and a pin adapted to adjust the length of the play of the leverin the loop, substantially as described.

4. In a device of the kind described, a take up connecting rod formed intwo parts having overlapping ends, a box shaped sleeve at the inner endof one part, a toothed section on the top face of the inner end of theother part slidingly engaging into the sleeve, a series of dogs on theinner face of the top of the sleeve engaging with the toothed section,abar on the sleeve engaging beneath the dogs, and means for raising saidbar to simultaneously disengage all the dogs, substantially as and forthe purpose described.

5. The combination with the cylinder levers of a brake apparatus, of atie or fulcrum bar having a take up joint, an adjuster rod or barbetween the levers beyond the fulcrum bar, and an adjustable looseconnection between one lever and the bar, whereby the piston travel maybe adjusted to a given length.

6. The combination with two oppositely moving levers of a car brakeapparatus, of a slack-take-up connecting bar therefor made in twosections, a guide sleeve at the end of one section, a toothed bar at theend of the other section fitting snugly into the sleeve, a series ofrecesses in theunder face of the top of the sleeve, and a series ofgravity dogs or pawls loosely seated in said recesses engaging the teethof the ratchet bar, substantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

FRANK ROBINSON.

\Vitnesses:

O. F. \IVOODARD, H. M. BURR.

